replace gen 1 ACI spine with new model

[michelvankessel]

Hi,

We are currently running a multi-pod fabric (version 4.2.7), with N9K-C9336PQ spine switches.

New spines will be the N9K-C9316D-GX 

I am trying to find a procedure for this swap and also for specific tips and tricks. 

Especially I would like to hear what can go wrong, upgrading from gen 1 to gen 3 spine switches in a multi-pod

Who has done this swap? or can tell where I can find more info about this swap? 

many thanks

Michel

[Claudia de Luna · Accepted solution]

Hi @michelvankessel 

I have run mixed generation fabrics in the past but not with the GX models so I do hope you will share your experience!

• Run the same code of course.  For your new N9K-C9316D-GX Spines your fabric will need to be on 4.2(2e) or later which you are!
• Check your optics!  That can be a big issue.  

Your approach is already very safe. You are replacing all your spines with a new identical model.

You may have already seen the documentation below, but just in case.

Fabric with mixed hardware or software

https://www.cisco.com/c/en/us/td/docs/dcn/whitepapers/cisco-application-centric-infrastructure-design-guide.html#Fabricwithmixedhardwareorsoftware

(Not as relevant for you as you are replacing Spines but in case this is next for your fabric)

Virtual Port Channel Migration - Migration of Nodes from a First-Generation Switch to a Second-Generation Switch

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/hw/aci_hig/guide/b_aci_hardware_install_guide/b_aci_hardware_install_guide_chapter_011.html#id_97986

[michelvankessel]

Thank you for your information @Claudia de Luna and @Ezzedine , and sorry for this late response. But we had some delay with the hardware delivery

So the only big issue I see, is the fact that the current mpod uplinks to the IPN switches, are on port eth1/35 and eth1/36. The new switches have only 16 ports

I probably need to remove the current ports from the mpod L3out, and add them back after the hardware is replaced. At least that is the plan. But if you have any tips, please let me know.

I am also wondering if I should do all of this with the switches in GIR mode? I have never worked with GIR in a HW replace situation.

In the meantime I did a DOA check, installed the same software version, and ran the clean script. Next step will be, installing the switches in the data center

thank you for all the info! I'll let you know how the swap went! 

Michel

[ECCOLE]

Can you be more specific when you say, "Check your optics! That can be a big issue"? 

[Ezzedine]

hello @michelvankessel 

you can either discover the new spines and move the Multi-Pod configuration manually or to replace the hardware sequentially following the suggested method from @Claudia de Luna "Virtual Port Channel Migration" to avoid the traffic loss, the difference is that the Spines dont run vPC between each others.

best regards.

Ezzedine